Method of producing aerosoltype package



Ap il 1964 H. A. BARNBY ETAL METHOD OF PRODUCING AEROSOL-TYPE PACKAGEOriginal Filed Aug. 24, 1959 INVENTORS r m, BHM NN c firm s flZA Y BH HEWm N TH sk R AM. 2H5 r BP an A H Q B United States Patent 3,131,077METHQD 0F PRODUCING AEROSOL- TYPE PACKAGE Herbert A. Barnby and Ralph H.Whitney, Toledo, ()hio,

assignors to Qwens-lilinois Glass Company, a corporation of GhioOriginal application Aug. 24, 1959, Ser. No. 835,545, new Patent No.3,014,607, dated Dec. 26, 1961. Divided and this application May 22,1961, Ser. No. 111,631 4 Claims. (Cl. 117-55) This application is adivision of application Serial No. 835,545, filed August 24, 1959, nowPatent No 3,014,607.

Our invention relates to aerosol-type packages or containers and methodsof producing them and more particularly to the provision of asubstantially overall plastic or thermoplastic protective coating whichcan and will expand in a preselected localized area and thus serve as atelltale, in the event the container has been fractured in that area andleaks pressurized contents at the fracture point.

In aerosol-type or pressure containers formed of glass, or the likematerial, they may, but do not necessarily, include a reduced neckportion and a head surmounting such neck. To this head is attached adispensing-type closure cap or fitment, such being hermetically sealedin place by spinning or otherwise contracting an attaching skint beneaththe head or over some other protuberance, into firm contact with theadjacent surface of the container. The container may be filled eitherprior to or following such closing.

Because such spinning or other procedure resorted to in contracting theattaching skirt into effective tight holding relationship with the glasssubjects the latter to considerable pressure or stress and in someinstances cracks or fractures the glass so that the container will leak,in normal use, it is necessary to provide reliable means for detectingor indicating the presence of any such leakers, or potential leakers,prior to placing the packages in the hands of the consuming public.

An object of our invention is to provide novel means for so applying anelastic protective coating of plastic, resinous or thermoplasticmaterial, to the exterior surface of an aerosol-type bottle, thatreadily observable expansion of the coating in a selected localizedisolated zone will occur, should there be a fracture in that zone ofsuch severity as to permit leakage of the pressurized contents.

Another important object of our invention is the provision of simple andeffective means which will prevent complete separation of broken glasssections and/or dispensing fitments from the package, under internalpressure.

Other objects will be in part apparent and in part pointed outhereinafter.

In the drawings:

FIG. 1 is a side elevational view of an aerosol-type package orcontainer incorporating our invention.

FIG. 2 is a fragmentary detail sectional view showing the protectivecoating bonded to the glass container except in a restricted annularneck area.

FIG. 3 is a view similar to FIG. 2 but showing the coating expandedunder the influence of pressurized content which has escaped from thecontainer through a neck fracture.

FIG. 4 is a sectional view taken along the line 44 of FIG. 1 but showsthe coating expanded in the neck zone to indicate leakage of thepressurized content.

FIG. 5 is a detail fragmentary sectional view illustrating means forpreventing adhesion of the thermo plastic coating and bonding agent tothe bottle in a restricted area.

On invention, in the illustrated embodiment, is in- 3,l3l,77 PatentedApr. 28, 1964 corporated in a pressure container of the well-knownaerosol-type. Although other specific forms of containers may beutilized, we, for present purposes, have shown the invention applied toa glass bottle or the like container 10 including a body portion 11formed with a diametrically reduced upstanding neck 12 which issurmounted by an enlarged head 13 or rim portion. This head pro vides adownwardly outwardly facing abutment or shoulder 14 and a relativelyflat top sealing surface '15 of annular form. A protective plastic or athermoplastic coating 16 formed for example of plastisol, or some vinylresin dispersion or suspension material incases substantially the entirebottle, such coating being securely bonded to the exterior surface ofthe container. A dispensingtype closure, or fitment 17, is telescopedover the head 13 and has an attaching skirt 18 spun over the abutment orshoulder 14 and into firm holding engagement with the upper marginalportion of the protective coating 16. A sealing element 19 is interposedbetween the closure and the top sealing surface 15' of the head '13. Acover 20 is provided for the dispensing fitment.

It is important that these pressure containers be coated with aprotective cushion-like or elastic, plastic or thermoplastic film, butit also is equally important that such film or coating should notpreclude ready detection of potentially dangerous fractures in thecontainers. As stated heretofore, these fractures, if they occur at all,almost invariably are in that area in which pressure of the tool isapplied to the glass as it affixes the closure or fitment to thecontainer, accordingly, we have provided means whereby, in the eventthere is leakage of pressurized contents through a fracture, the coatingwill quickly expand or bulge in a localized zone and afford visibleevidence of the abnormal conditions.

The protective coating is secured to the glass container through aprocedure involving first applying a prime coat or bonding agent 21 inthe form of a thin film, to the glass surface in those areas in whichadhesion of the protective coating to the glass is desired. The primecoat, or bonding agent 2.1, may Well as broadly defined as an aminoalkylalkoxy silane, and it has been found that excellent results arealso obtainable when the silane has at least one alkyl group and atleast one ethoxy group directly linked to the silicon atom. Further,however, a primer composition containing an epoxy resin and an alkylmethacrylate polymer may be applied as a film to the silane referred toabove, but preferably it is incorporated as a component of a singlemixture including the latter, thus avoiding the need for a secondcoating step, insofar as application of the bonding agent per se isconcerned.

We provide means for neutralizing the effectiveness of the bonding agentin the neck area or a selected exterior surface portion of the containerso that the protective coating 16 may expand or bulge in this area,should the bottle be seriously defective in the neck zone. Suchexpansion or bulging occurs only if the fractures 22 (FIG. 4) are ofsuch character as to open and allow leakage of pressurized content ofthe package, when subjected, for example, to a hot water bath. This hotwater bath involves immersing tilled sealed packages in a bath of waterheated to about F. to F. for a period of about 3 to 4 minutes. Suchtreatment raises the temperature of the contents substantially and thusincreases the internal pressure with resultant leakage of such contentsin the event the structural defect, or fracture, is of really seriousnature. Expansion of the coating in an annular zone about the fractureprovides clearly visible evidence of the defect.

Obviously, provision must be made whereby the protective coating mayexpand freely relative to land independently of the neck when thedescribed leakage occurs. To this end, We may either omit the bondingagent 21 in a selected isolated area 23 (FIGS. 24) encircling the neck12, or as in FIG. 5, coat the glass surface in this same area or perhapssome other area, or zone, as determined by the specific form of thecontainer, with a neutralizing material 24 which Will preclude anyeffective adhesion of the prime coating and therefore the protectivecoating to the glass. Such neutralizing material may well be glycerin,liquid silicone, water containing a wetting agent, the latter forexample being one of the welhknown detergents such as that sold underthe trademark Joy or perhaps a dilute Water suspension of polyethylene,as examples.

Modifications may be resorted to within the spirit and scope of theappended claims.

We claim:

1. In the method of aflixing an elastic protective plastic casing to theexterior surface of a frangible aerosol-type container and providingmeans permitting localized outward expansion of the casing in a neckzone of potential fracture incident to leakage of pressurized contentsat the fracture point, the steps consisting in applying to the explyinga film of a bonding agent to substantially the en-' tire exteriorsurface of the container and over the neutralizing material and applyinga protective film of elastic resinous material to the entire surface ofsaid bonding agent.

2. The method according to claim 1 wherein the neutralizing material isa dilute suspension of polyethylene.

3. The method according to claim 1 wherein the neutralizing material isglycerin.

4. The method according to claim 1 wherein the neutralizing material isa liquid silicone.

References Cited in the file of this patent UNITED STATES PATENTS286,823 Hopkins Oct. 16, 1883 1,304,749 Divine May 27, 1919 2,917,197Glover et al. Dec. 15, 1959 2,957,779 Bolton Oct. 25, 1960 3,014,607Barnby et a1. Dec. 26, 1961 3,018,106 Satchell et a1. Jan. 23, 1962

1. IN THE METHOD OF AFFIXING AN ELASTIC PROTECTIVE PLASTIC CASING TO THEEXTERIOR SURFACE OF A FRANGIBLE AEROSOL-TYPE CONTAINER AND PROVIDINGMEANS PERMITTING LOCALIZED OUTWARD EXPANSION OF THE CASING IN A NECKZONE OF POTENTIAL FRACTURE INCIDENT TO LEAKAGE OF PRESSURIZED CONTENTSAT THE FRACTURE POINT, THE STEPS CONSISTING IN APPLYING TO THE EXTERIORSURFACE IN SAID ZONE A MATERIAL FOR NEUTRALIZING THE EFFECTIVNESS OF ABONDING AGENT WHICH IS TO BE APPLIED SUBSTANTIALLY AS AN OVERALL COATINGFOR THE CONTAINER, APPLYING A FILM OF A BONDING AGENT TO SUBSTANTIALLYTHE ENTIRE EXTERIOR SURFACE OF THE CONTAINER AND OVER THE NEUTRALIZINGMATERIAL AND APPLYING A PROTECTIVE FRILM OF ELASTIC RESINOUS MATERIAL TOTHE ENTIRE SURFACE OF SAID BONDING AGENT.